U.S. patent number 8,234,217 [Application Number 10/592,339] was granted by the patent office on 2012-07-31 for method and system for selectively providing access to content.
This patent grant is currently assigned to Thomson Licensing. Invention is credited to Mike Arthur Derrenberger.
United States Patent |
8,234,217 |
Derrenberger |
July 31, 2012 |
Method and system for selectively providing access to content
Abstract
A method of operating a digital program playback device,
including: receiving, via a first communications network, a data
stream including an encrypted data portion representative of a
program; identifying, from the received data stream, an identifier
associated with the program; transmitting the program identifier
and a device identifier associated with the digital program
playback device to an authorization device via a second
communications network; receiving, via the second communications
network, a decryption key in response to the transmission; and,
decrypting the data stream using the decryption key and generating
an output signal for playback of the program.
Inventors: |
Derrenberger; Mike Arthur
(Fishers, IN) |
Assignee: |
Thomson Licensing (Boulogne
Billancourt, FR)
|
Family
ID: |
34973094 |
Appl.
No.: |
10/592,339 |
Filed: |
March 17, 2005 |
PCT
Filed: |
March 17, 2005 |
PCT No.: |
PCT/US2005/009055 |
371(c)(1),(2),(4) Date: |
September 11, 2006 |
PCT
Pub. No.: |
WO2005/104000 |
PCT
Pub. Date: |
November 03, 2005 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20070198414 A1 |
Aug 23, 2007 |
|
Current U.S.
Class: |
705/51; 380/266;
380/228; 726/30; 726/25; 713/193; 705/52; 380/43; 725/25; 380/231;
705/57; 380/281; 726/26; 713/164; 713/155; 725/153; 725/34; 725/31;
386/231 |
Current CPC
Class: |
G11B
20/00181 (20130101); H04N 21/44055 (20130101); H04L
9/065 (20130101); G11B 20/00224 (20130101); H04N
21/23473 (20130101); H04N 21/42684 (20130101); H04N
21/25833 (20130101); H04N 21/4135 (20130101); G06F
21/10 (20130101); H04N 21/8355 (20130101); H04N
21/4367 (20130101); H04N 21/8549 (20130101); H04N
21/4334 (20130101); G11B 20/0021 (20130101); H04N
21/63345 (20130101); H04N 7/1675 (20130101); H04N
21/23476 (20130101); G11B 20/00086 (20130101); H04N
21/4627 (20130101); H04N 21/2351 (20130101); H04N
21/43853 (20130101); H04N 21/8352 (20130101); H04N
21/26613 (20130101); H04N 21/6181 (20130101); H04N
21/23895 (20130101); H04N 21/2541 (20130101); H04N
21/25816 (20130101); H04N 21/4353 (20130101); H04L
2209/603 (20130101) |
Current International
Class: |
G06F
21/00 (20060101) |
Field of
Search: |
;713/193 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2 367 925 |
|
Apr 2002 |
|
GB |
|
8-23315 |
|
Jan 1996 |
|
JP |
|
8-190345 |
|
Jul 1996 |
|
JP |
|
11-331310 |
|
Nov 1999 |
|
JP |
|
2001-103047 |
|
Apr 2001 |
|
JP |
|
2002-344440 |
|
Nov 2002 |
|
JP |
|
WO 02/13032 |
|
Feb 2002 |
|
WO |
|
WO 02/065750 |
|
Aug 2002 |
|
WO |
|
WO 03/088673 |
|
Oct 2003 |
|
WO |
|
Other References
Jian Zhang et al. "A flexible content protection system for
media-on-demand" Multimedia Software Engineering, 2002.
proceedings. fourth international symposium on Dec. 11-13, 2002
Picataway, NJ, USA, IEEE, Dec. 11, 2002, pp. 272-277, XP010632760
ISBN: 0-7695-1857-5 the whole document. cited by other .
Rosenblatt B et al.: "Digital Rights Management, Passage" Digital
Rights Management: Business and Technology, New York, NY: M&T
Books, US2002, pp. 79-88, 95, XP002341140 ISBN: 0-7645-4889-1 the
whole document. cited by other .
Van Moffaert A et al: "Digital Rights Management: DRM is a key
enabler for the future growth of the broadband access market, and
the telecom/networking market in general" Alcatel
Telecommunications Review, Alcatel, Paris Cedex, FR. Apr. 2003.
XP0070005930 ISSN: 1267-7167 the whole document. cited by other
.
Thomson Multimedia: "SmartRight Contribution to Rights Management
& Protection Specifications" Thomson Multimedia, May 22, 2002,
XP002341140 ISBN: 0-7645-4889-1 the whole document. cited by other
.
Search Report dated Sep. 27, 2005. cited by other.
|
Primary Examiner: Flynn; Nathan
Assistant Examiner: Wright; Bryan
Attorney, Agent or Firm: Shedd; Robert D. Kiel; Paul P.
Claims
What is claimed is:
1. A method of operating a digital program playback device,
comprising: receiving, via a first communications network, a
plurality of data streams representative of a program including an
encrypted data portion and an unencrypted data portion;
identifying, from the received data stream, an identifier uniquely
associated with the program; transmitting the program identifier
and a device identifier that identifies the digital program
playback device to an authorization device via a second
communications network for authorization based on the program
identifier and the device identifier, wherein the second
communications network is distinct from the first communications
network; receiving, via the second communications network, a
decryption key in response to the transmission, once authorization
is confirmed; and decrypting the data stream using the decryption
key and generating an output signal for playback of the program,
wherein the unencrypted data portion is processed for output before
the encrypted data portion.
2. The method of claim 1, wherein the unencrypted data stream
representative of a beginning portion of the program, and an output
signal in response to the unencrypted data stream is generated
prior to said decryption key being received.
3. The method of claim 1, wherein the digital program playback
device comprises a mobile user terminal, and the second
communications network comprises a two-way pager network.
4. A method of transmitting a program for playback on a digital
playback device, the method comprising the steps of: generating a
plurality of data streams representative of the program including
an encrypted data portion and an unencrypted data portion to be
processed for output before the encrypted data portion; storing a
decryption key for decrypting the encrypted data stream on a key
server; storing playback rights information associated with the
digital playback device in a database; transmitting, to the digital
playback device, via a first communications network, the encrypted
data stream; receiving, via a second communications network, a
request from the digital playback device to access the program, the
request including an identifier uniquely associated with the
program and an identifier that identifies the digital playback
device, wherein the second communications network is distinct from
the first communications network; determining whether the digital
playback device has access rights to the program according to the
database based on the program identifier and a device identifier;
and transmitting the decryption key to the digital playback device
in response to the determining step.
5. The method of claim 4, wherein the unencrypted data stream is
representative of a beginning portion of the program.
6. The method of claim 4, wherein the digital playback device
comprises a mobile user terminal, and the second communications
network comprises a two-way pager network.
7. A method of operating a digital program recording device, the
method comprising: receiving, via a first communications network, a
data stream including a first data portion representative of a
first part of a program and an encrypted data portion
representative of a second part of said program; identifying, from
the received data stream, an identifier uniquely associated with
the program; transmitting the program identifier and a device
identifier that identifies the digital program recording device to
an authorization device via a second communications network for
authorization based on the program identifier and the device
identifier, wherein the second communications network is distinct
from the first communications network; receiving, via the second
communications network, a decryption key in response to the
transmission once authorization is confirmed; and decrypting the
data stream using the decryption key and generating an output
signal for recording the program wherein the first data portion is
processed for output before the encrypted data portion.
8. The method of claim 7, wherein the first part of the program is
a beginning portion of the program, and further comprising the step
of generating an output signal in response to the first data
portion prior to said decryption key being received.
9. The method of claim 7, wherein the first data portion is either
unencrypted or encrypted using a common key.
10. The method of claim 7, wherein the second communications
network comprises a two-way pager network.
11. A method of operating a computer program executing device, the
method comprising: accessing, via a first communications network, a
plurality of data streams representative of a program including a
first data portion representative of a first part of said program
and an encrypted data portion representative of a second part of
said program; identifying, from the accessed data, an identifier
uniquely associated with the program; transmitting the program
identifier and a device identifier that identifies the computer
program executing device to an authorization device via a second
communications network for authorization based on the program
identifier and the device identifier, wherein the second
communications network is distinct from the first communications
network; receiving, via the second communications network, a
decryption key in response to the transmission once authorization
is confirmed; and decrypting the encrypted data portion using the
decryption key and generating an output for executing the program,
wherein the first data portion is processed for output before the
encrypted data portion.
12. The method of claim 11, wherein the first part of the program
is a functionally limited version of said computer program, and
further comprising the step of generating an output signal in
response to the first part prior to said decryption key being
received.
13. The method of claim 10, wherein the first data portion is
either unencrypted or encrypted using a common key.
14. The method of claim 10, wherein the second communications
network comprises a two-way pager network.
15. A computer program product stored on a non-transitory computer
readable medium for use with a computing device and executing on a
processor, the computer program product comprising: a first data
portion representative of a first part of said computer program
product, the first data portion received via a first communications
network; an encrypted data portion representative of a second part
of said computer program product, the encrypted portion received
via a first communications network; code for identifying a program
identifier uniquely associated with the computer program product
from the first data portion, and a device identifier that
identifies the computing device; code for transmitting the program
identifier and device identifier to an authorization device via a
second communications network for authorization based on the
program identifier and the device identifier, wherein the second
communications network is distinct from the first communications
network; code for receiving a decryption key in response to the
transmission; and code for decrypting the encrypted data portion of
the computer program product using the decryption key and
generating an output for executing the computer program product,
wherein the first data portion is processed for output before
generating the output based on the encrypted data portion.
16. The computer program product of claim 15, wherein said output
for executing the computer program product comprises an output for
activating a functionality of said computer program product
corresponding to said second portion.
17. The computer program product of claim 16, wherein the first
part of the computer program product is representative of a
functionally limited version of said computer program product, and
further comprising the step of generating an output signal in
response to the first data portion prior to said decryption key
being received.
18. The computer program product of claim 15, wherein the first
data portion is either unencrypted or encrypted using a common
key.
19. The computer program product of claim 15, wherein the second
communications network comprises a two-way pager network.
20. A method for selectively providing a client device access to
content, said method comprising: accessing a first data portion
representative of a first part of said content and an encrypted
data portion representative of a second part of said content, the
first data portion and the encrypted data portion received via a
first communications network; identifying, from the accessed data,
an identifier uniquely associated with the content; transmitting
the program identifier and a device identifier that identifies the
client device to an authorization device via a second communication
network for authorization based on the program identifier and the
device identifier, wherein the second communications network is
distinct from the first communications network; receiving a
decryption key in response to the transmission; generating an
output signal in response to the first data portion for accessing
the first part of the content prior to said decryption key being
received; and decrypting the encrypted portion of the data using
the decryption key and generating an output signal in response to
the decrypted portion for accessing the second part of the content,
wherein the first part of the content is processed for output
before the encrypted portion.
21. The method of claim 20, wherein said content comprises at least
one of a computer program product, an audio presentation and an
audio/visual presentation.
22. The method of claim 20, wherein said providing access comprises
at least one of executing a computer program product, playing an
audio presentation, playing an audio/visual presentation, recording
an audio presentation and recording an audio/visual
presentation.
23. The method of claim 20, wherein said transmitting and receiving
is via a two-way pager network.
24. The method of claim 20, wherein the first data portion is
either unencrypted or encrypted using a common key.
Description
This application claims the benefit, under 35 U.S.C. .sctn.365 of
International Application PCT/US2005/009055, filed Mar. 17, 2005,
which was republished in accordance with PCT Article 21(2) on Jan.
5, 2006 in English.
FIELD OF THE INVENTION
The present invention relates to methods and systems for
restricting access to content, such as computer programs, audio
programs and audio/visual programs.
BACKGROUND OF THE INVENTION
Widespread distribution of content, such as computer programs,
audio programs and audio/visual programs, such as via transmission
and/or prerecorded media (like CDs and DVDs), is common place.
Preventing unauthorized access to distributed high value content
has proven problematic however, particularly in the case of air
broadcasts and pre-recorded media. Current methods use a variety of
techniques of access protection including the use of Smart Cards,
keys embedded with the content that can be decrypted using common
keys, and keys that must be typed to unlock a computer program, for
example.
Digital Rights Management is typically not integrated with copy
protection systems to provide a comprehensive solution. For
example, while copy protection schemes may exist for closed systems
(e.g., satellite providers) these systems do not effectively
integrate Digital Rights Management. Further, Digital Rights
Management systems do not effectively exist for computer programs,
and no effective solution has been developed for mobile devices.
Further still, means of providing specific keys for specific
content do not effectively exist. Finally, many systems have no
means of reliably ensuring access to a bidirectional or two-way
communications network to manage the copy protection process and
associated digital rights. Improved mechanisms and techniques for
overcoming the aforementioned problems are highly desired.
SUMMARY OF THE INVENTION
A method of operating a digital program playback device, including:
receiving, via a first communications network, a data stream
including an encrypted data portion representative of a program;
identifying, from the received data stream, an identifier
associated with the program; transmitting the program identifier
and a device identifier associated with the digital program
playback device to an authorization device via a second
communications network; receiving, via the second communications
network, a decryption key in response to the transmission; and,
decrypting the data stream using the decryption key and generating
an output signal for playback of the program.
BRIEF DESCRIPTION OF THE DRAWINGS
Understanding of the present invention will be facilitated by
considering the following detailed description of the preferred
embodiments of the present invention taken in conjunction with the
accompanying drawings, in which like numerals refer to like parts,
and:
FIG. 1 illustrates a block diagrammatic view of a system according
to an aspect of the present invention;
FIG. 2 illustrates a block diagrammatic view of a system according
to an aspect of the present invention, and being well suited for
use with computer software content;
FIG. 3 illustrates a block diagrammatic view of a system according
to an aspect of the present invention, and being well suited for
use with audio/visual content;
FIG. 4 illustrates a block diagrammatic view of an exemplary
playback process being suitable for use with the system of FIG.
3;
FIGS. 5A and 5B illustrate block diagrammatic views of
architectures that may be utilized in a client device according to
an aspect of the present invention;
FIG. 6 illustrates a graphical representation of a mechanism to
account for latencies in network transmissions according to an
aspect of the present invention; and,
FIG. 7 illustrates a method according to an aspect of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is to be understood that the figures and descriptions of the
present invention have been simplified to illustrate elements that
are relevant for a clear understanding of the present invention,
while eliminating, for the purpose of clarity, many other elements
found in typical copy protection and digital rights management
systems and methods. Those of ordinary skill in the art may
recognize that other elements and/or steps are desirable and/or
required in implementing the present invention. However, because
such elements and steps are well known in the art, and because they
do not facilitate a better understanding of the present invention,
a detailed discussion of such elements and steps is not provided
herein.
According to an aspect of the present invention, a centralized
mechanism to use a communication network, such as a two-way paging
network, as a means to access decryption keys to play-back
encrypted content distributed using a variety of delivery methods
may be provided. The system may enforce Digital Rights Management
(DRM) and Copy Protection (CP) schemes and provide for wireless
access to support fixed location and mobile devices (such as
desktop personal computers and laptop personal computers, and fixed
and mobile set-top boxes and display devices, for example).
Further, the utilized network may provide for "always-on"
functionality.
According to an aspect of the present invention, a system may
typically incorporate content and key servers, hardware
implementation of a security module in client devices, and a method
to handle inherent latencies in the communication network used, to
provide for low cost decryption key provision to facilitate copy
protection and/or digital rights management schemes. According to
an aspect of the present invention, such a system and method may
actually encourage content copying, as there is no advantage to a
"pirate" to copy content containing media that is encrypted but
that itself lacks the necessary decryption keys.
Referring now to FIG. 1, there is shown a system 100 according to
an aspect of the present invention. System 100 generally includes
content server(s) 110, key server(s) 120, content distribution
measures 130 (such as wireless and/or wired transmission systems,
like terrestrial and satellite television networks, the global
interconnection of computers and computer networks commonly
referred to as the Internet and cable television and computer
networks; and media distribution channels, like retail distribution
chains), client device(s) 140, and communications network 150.
Content (e.g., computer software, audio and/or video programs) is
generally created, digitized if necessary, and stored on content
server(s) 110. In an exemplary configuration, meta-data regarding
the content is associated with the content to uniquely identify it.
Key server(s) 120 include database(s) that include content
encryption/decryption keys, the unique content identifiers,
information as to what devices 140 are authorized devices, what
devices are playing or recording, or have authority to play or
record content, and how many times each device 140 has played or
recorded the specific content, by way of non-limiting example.
Content may be executed, played and/or recorded using device(s)
140, provided content server 110 permits it. Access to encrypted
content occurs after a client playback device 140 securely obtains
a corresponding decryption key from key server(s) 120. Permissions
may be communicated via network 150, for example.
In an exemplary embodiment, content may be provided via content
distribution measures 130, e.g., via broadcast or media
distribution network(s). In order to record the content, a
permission seeking device 140 may securely contact key server 120
via network 150 to determine if that device may copy the subject
content. The subject content may be identified through companion
meta-data, broadcast channel/time information, or the content
itself, for example. Key server 120 may contact content server 110
over communication link 115 to determine Digital Rights Management
(DRM) information associated with the subject content, e.g.,
whether the requesting device 140 is authorized to play and/or
record the subject content. If permissible, key server 120 may
securely return a unique content identifier and a recording key via
network 150 to the requesting device 140. The requesting device.
may then record the subject content using the information returned
by key server 120, e.g., decrypting and/or encrypting keys. The
recorded content may be encrypted for storage using such an
encrypting key. The storage key may be different from that used to
store the content on content server 110, and/or that protects the
content prior to authorization from key server 120 to access the
same. Alternatively, the content may be stored in the encrypted
form it is received in, and the decryption key securely stored for
later use.
By way of non-limiting example only, network 150 may take the form
of a wireless communication network, like a two-way pager network.
Communications via network 150, e.g., a pager network, may be
encrypted (e.g., between device 140 (FIG. 1) and key server 120
(FIG. 1). While not critical, a two-way pager network may be
particularly advantageous for use as at least part of network 150
due to cost considerations. It is expected that such a network will
provide for relatively low costs per transaction, while providing
broad accessibility across wide geographic regions. However, such a
network may introduce inherent latencies in communications between
device(s) 140 and key server 120. For example, latencies on the
order of 1, 5 or even 10 minutes may be experienced. However, a
two-way pager network solves the connection problem for fixed
location client devices, such that telephone modems and other
broadband connections are not needed. Additionally, the same system
can be-used to provide connectivity for mobile client devices.
Communications over network 150 may be secured to frustrate
unauthorized access thereto, such as by encrypting them using a
network 150 security key, or key pair.
Referring now also to FIG. 2, there is shown a system 200 according
to an aspect of the present invention and being well suited for use
with computer software content. Like references identify like
elements in FIGS. 1 and 2. System 200 further includes program
creation system 210, which may typically include multiple elements
of hardware/software used to author computer executable code.
Computer software content may be created using system 210. The
content may then be provided to content server 110, where it may be
encrypted and stored. Corresponding encryption/decryption key(s)
and a content identifier may be provided to key server 120. A
symmetrical key, or public/private key pair may be used. The
program identifier may be in the clear, i.e., not encrypted. The
encrypted content may be distributed using content distribution
measures 130, such as via CD, DVD or a broadband network, for
example. Computer program execution may occur at personal computer
140, upon obtaining a corresponding decryption key from key server
120 via network 150.
By way of further non-limiting example, key server 120 may create a
corresponding entry in one or more database(s) that reflects the
program encryption/decryption key(s), the unique program
identifier, information regarding what devices are authorized
devices, what devices are executing the content, and how many times
the device has executed or been authorized to execute the specific
content. The present invention contemplates various possible
implementations. In a simplified embodiment, a device may re-query
a key server for each installation, execution or playback.
Alternatively, perpetual or time-based digital rights management
information can be provided in a secure processor. In such a case,
the key may be valid for one or for multiple installations,
executions or playbacks, until key expiration, time-out, or a
predetermined number of allowed plays has occurred.
Encrypted programs may be offered to be freely copied, as they do
not contain activation keys. The encrypted content can be
distributed using any type of content distribution measure (e.g.,
shipped as DVDs, Internet file, etc.). Computer execution of the
encrypted program can only occur after decryption of the same,
which requires a personal computer device 140 obtain the decryption
key from key server 120 via network 150.
Referring now also to FIG. 3, there is shown a system 300 according
to an aspect of the present invention, and being well suited for
use with audio/visual content. Like references again identify like
elements in FIGS. 1 and 3. System 300 further includes content
creation system 310, which may typically include cameras,
microphones and hardware/software commonly used to record
audio/visual presentations, like recordings, movies and television
shows. Audio/visual content may be created and digitized using
system 310. The content may again be provided to content server
110, where it may be encrypted and stored. A unique content
identifier may be associated with the encrypted content as
meta-data, and be provided in the clear. Corresponding.
encryption/decryption keys and the content identifier may be
provided to, and stored by key server(s) 120. The encrypted content
may be distributed using content distribution measures 130, such as
via CD, DVD or a broadcast network, for example. Playback may occur
at playback device 140, such as a device akin to a digital receiver
or DVD player, upon obtaining a corresponding decryption key from
key server 120 via network 150.
By way of further non-limiting example, key server 120 may create a
corresponding entry in one or more database(s) that reflects the
program encryption/decryption key(s), the unique program
identifier, information regarding what devices are authorized
devices, what devices are authorized to play and/or record the
content, and how many times a device has accessed or been
authorized to access specific content. Encrypted programs may be
offered to be freely copied, as they do not contain activation
keys. The encrypted content can be distributed using any type of
content distribution measure (e.g., broadcast transmission, shipped
as DVDs, Internet files, etc.). Copying or playback of the
encrypted program can only occur after decryption of the same,
which requires a player device 140 obtain the decryption key from
key server 120 via network 150.
Referring now also to FIG. 4, there is shown a block diagrammatic
view of an exemplary playback process 400 being suitable for use
with system 300 of FIG. 3. A playback device 140 determines the
content identifier associated with the content to be played, such
as by reading it from a media, such as a DVD or CD, that contains
the clear-text identifier and encrypted content. Playback device
140 may then contact key server 120 via network 150, which may take
the form of a two-way pager network, for example. Key server 120
authenticates player device 140 and the unique program identifier.
If playback is permitted, e.g., if the content still has play
rights, key server 120 sends a corresponding decryption key (that
may be a symmetrical key or a corresponding part of a key pair,
both by way of non-limiting example) to playback device 140 using
network 150 in a secure manner. Playback device 140 may use the
acquired key to decrypt the content for playback and generate an
output signal 145 for playback of the decrypted program content on
a display device, such as via a display device communicatively
coupled to the playback device (such as via RCA cables or an HDMI
interface, for example).
Referring now also to FIG. 5A, there is shown a block diagrammatic
view of an architecture 500A that may be utilized in a client
device, such as device 140 of FIGS. 1-4, according to an aspect of
the present invention. Architecture 500A may serve to implement the
overall security policy associated with content recording for a
client device 140, and may even be integrated into the device's
audio/video decoder, for example.
By way of non-limiting example, architecture 500A may include an
input 510 suitable for receiving encrypted content from content
distribution measures 130 (FIG. 1). Input 510 may take the form of
an audio/visual data decoder or buffer for receiving a data stream
from an antenna or network connection, or media drive, for example.
Received data may be stored in a storage device 540, such as a
hard-drive, and read there-from using a read/write interface 530.
Received data may be provided to an encryptor/decryptor 520. A
content key register 550 may store keys and corresponding content
identifiers for use by encryptor/decryptor 520. Architecture 500A
may further include a modem 560 for communicating via network 150,
and a device identifier and network 150 security key store 570.
Store 570 may store a device identifier of a particular device 140
and a network security key for network 150. Architecture 500A may
operate responsively to a security processor 580. A/V or content
data may be provided from any suitable source serving as medium 130
(such as a satellite tuner/demodulator, home network, or
cable/demodulator). Network 150 communications (e.g., wireless
pager transmissions) are received by modem 560 (such as a pager
network modem).
Generally, according to an aspect of the present invention, it is
undesirable to store A/V content in the clear on device 540.
Accordingly, it is generally desirable to encrypt the A/V content
before it is stored. A corresponding encryption key and Unique
Content ID may be provided by key server 120 and sent via network
150 using modem 560. This encryption key may be used by
encryptor/decryptor 520 to encrypt the content before placing it in
storage device 540.
Referring now also to FIG. 5B, there is shown a block diagrammatic
view of an architecture 500B that may be utilized in a client
device, such as device 140 of FIGS. 1-4, according to an aspect of
the present invention. Like references identify like elements in
FIGS. 5A and 5B. According to an aspect of the present invention,
architecture 500B may serve to implement the overall security
policy associated with content playback for a client device 140,
and may even be integrated into the device's audio/video decoder,
for example. Architecture 500B additionally includes an ANV decoder
515 and an encryptor/decryptor 525, that optionally may be the same
encryptor/decryptor element 520. Again, security processor 580
controls authentication and key handling. Public/private key pair
encryption techniques may be used. After a device 140 and
particular content has been authenticated, responsively to device
and content identifiers being sent to key server 120, security
processor 580 receives the encrypted content key from key server
120 (via, network 150 and modem 560). The content decryption key
may then be written into registry 550, which is not generally
accessible except by security processor 580, and used to decrypt
the associated content using encryptor/decryptor 525 for content
decoding using decoder 515. The content may be recovered from store
540 and decrypted, for example.
Referring now also to FIG. 6, there is shown a graphical
representation of a mechanism to account for latencies in
transmissions via network 150 according to an aspect of the present
invention. As set forth, network 150 may introduce latency into
communications between device(s) 140 and key server(s) 120. Too
much latency in the system and the user may not find the system
usable. In order to hide the transmission latency, a first portion
of the program data stream, such as the first few minutes (e.g.
5-10minutes) of an audio/visual program, may be permitted to be
accessed (e.g., executed, played and/or recorded) before the
content has been identified by key server 120 and/or content server
110, and the result returned to a device 140. Such execution may
correspond to limited functionality of a computer program product.
Such playing or recording can be used to implement the pause
feature associated with a digital video recorder (DVR) (and
therefore set a limit on how long content can be paused without
having rights to record the content). The recording of program
content during this interval can be stored in the clear or
encrypted using a common encryption key that may be stored in
multiple devices 140.
By way of further, non-limiting example, a first portion 610 of
program content 600 may be permitted to be executed, played and/or
recorded prior to acquisition of a key from key server 120 by
either having this portion un-encrypted (i.e., in the clear), or
encrypted using a key a client device already has access to.
Portion 610 may correspond to a limited functionality, optionally
in terms of time or program functionality, of computer program
content. In the case of audio and/or video content, portion 610 may
correspond to a portion of the overall program, such as a first few
minutes. After some point 620, a portion 630 of the content is
protected using a key to be acquired from key server 120 (e.g.
encrypted).
Such a mechanism may present numerous advantages. Third party
content distribution may be encouraged. Furthermore, content is
identified before it is recorded. This prevents unauthorized
execution, playing and/or recording of the content. Digital Rights
Management (DRM) is integrated centrally at the key server(s). The
key server(s) may track the permissible rights of each individual
client device, or group of devices. If a particular device, or
group of devices, has exceeded permissible execution, playing
and/or recording rights, a key will not be issued to a requesting
client device. Further, if customer billing information is
provided, then DRM can be administered on a per customer basis
(rather than on a device basis). Finally, content encryption can be
segmented by any level of granularity. For example, each recorded
piece of content could have a unique encryption key. To reduce
latencies, a large number of keys may optionally be stored in the
security architecture.
Referring now also to FIG. 7, there is shown a block diagrammatic
representation of a method or process flow 700 according to an
aspect of the present invention. Method 700 may be well suited for
use with the system of FIG. 3 and process of FIG. 4. Analogous
methodology may be used for recording content, or executing
content, for example.
Method 700 includes receiving 710 a data stream indicative of a
program via a first communications network. An identifier
associated with the program is identified in block 720 from the
received data stream. The program identifier is then transmitted
(block 730) along with a device identifier associated with the
accessing device, to an authorization device via a second
communications network. A decryption key is received in block 740
via the second communications network, in response to transmission
730. The data stream may then be decrypted, and an output signal
indicative of the decrypted data stream is output in block 750
using the received decryption key.
The received data stream may include a data portion representative
of a first part of the program, and an encrypted data portion
representative of a second part of the program. The first data
portion may be generally accessible by the receiving device so as
to be processed and used to output a signal (block 760) indicative
of the first part of the program, independent of receipt of the
decryption key for the second part of the program. In one exemplary
embodiment, the data portion representative of the first part of
the program is unencrypted. In an alternative exemplary embodiment,
the data portion may be encrypted using a common key to which the
receiver has access. The first data portion may thus be used to
output a signal indicative of the first part of the program in
block 760, such as prior to the decryption key being received in
block 740. The steps of transmitting 730 and receiving 740 may be
accomplished using a two-way pager network.
It is to be understood that the forms of this invention as shown
are merely exemplary embodiments. Various changes may be made in
the function and arrangement of parts; equivalent means may be
substituted for those illustrated and described; and certain
features may be used independently from others without departing
from the spirit and scope of the invention as defined in the
following claims.
* * * * *